A number of prior art load cells lay claim to the ability of being less sensitive or compensating for off-center loading. Such devices vary in their configurations and in the degrees of success in meeting the objective.
The present invention seeks to provide a load cell which eliminates entirely sensitivity to off-center loading within the operational range for which it is designed, rather than merely compensating for or reducing the effects of such loading. This objective is realized in the invention through a very simplified structure which lends itself to convenient lower cost manufacturing and in which the spring movement sensing element of the load cell is easily calibrated on two orthogonal axes to assure precision operation. The essence of the invention resides in the use of two circular cross section cantilever springs which are mounted in a common vertical plane with the center axis of the movement sensing device, in this case a linear variable differential transformer (LVDT) having a movable and adjustable core element.
Other advantageous features of the invention will become apparent to those skilled in the art during the course of the following detailed description .